Terry has firmly denied using a racist slur against Ferdinand after video footage emerged on Sunday showing him uttering what some have interpreted as such.

The flashpoint occurred in the 85th minute of the match, when it is alleged that Terry mouthed the words 'you ******* black ****' towards Ferdinand.

Terry said that he thought Ferdinand had accused him of making a racist slur and "responded aggressively, saying that I never used that term". Chelsea have suggested that Terry only used the offending words as part of a longer sentence denying any racism.

The camera shot of Terry was obstructed at a crucial juncture by the defender's Chelsea and England team-mate Ashley Cole, who is expected to be a key witness in the investigation.

However, it is understood Ferdinand has told QPR he was entirely unaware of any race row until after Sunday's game, when Terry approached him to clear the air.

It is this uncertainty which prompted Rangers to refer the matter to the FA in an attempt to clear it up once and for all.

However, racism claims in football are notoriously hard to prove, even when the alleged victim is convinced they were abused.

Terry is set to remain England captain during the FA probe, even if it continues into next month's friendly double-header with Spain and Sweden.

That could prove extremely awkward should Ferdinand's older brother Rio earn an international recall, especially as Terry regained the armband from the Manchester United star after being stripped of it following allegations about an affair with the ex-partner of Wayne Bridge.

Being found guilty of racism would have even more serious consequences both on and off the field for Terry.

As well as a fine and/or suspension, his very international future would be in jeopardy as well as his position as Chelsea captain.